We are requesting funds for a 500 MHz Nuclear Magnetic Resonance (NMR) instrument with supporting accessories and a remote work station for data processing. The NMR instrumentation includes a 11.75 Telsa magnet, console to control data acquisition and processing, state-of-the-art accessories which allow for both proton and X-nucleus experiments, devices for providing dry cool air, and data storage devices. We are also requesting funds for a work station to be used for off-line data processing. The NMR instrumentation will be used to study a variety of biological systems including, but not limited to, nucleic acids, proteins, and carbohydrates. The NMR projects are aimed at the determination of structural parameters and the relationship between these parameters and the biological function of the molecules. Several of the projects also investigate the interactions between molecules. With recent technological advances, NMR can now compete with X-ray crystallography and has become a powerful technique for studying the solution properties of biomolecules. The major advance, which we will be taking advantage of, is the advent of two-dimensional NMR techniques. These techniques, and the complexity of the biomolecules, demand the high field and state-of-the-art instrumentation but provides a powerful multinuclear technique for the determination of macromolecular structure and dynamics.